Problem: Which of these numbers is composite? ${35,\ 37,\ 43,\ 67,\ 73}$
A composite number is a number that has more than two factors (including 1 and itself). 37, 43, 67, and 73 each have only two factors. The factors of 35 are 1, 5, 7, and 35. Thus, 35 is the composite number.